Road to HIV vaccine still clear, despite disappointing trial results
Clifford Akumu
The halting of the biggest HIV vaccine trial, the HVTN 702 study, early for non-efficay in preventing the disease, has caused disappointment far and wide.
Researchers, advocates, people living with the virus and global community had pegged their hope on the vaccine candidate.
Regrettably, the results were futile, forcing the US National Institute of Allergy and Infectious Diseases (NIAID) to stop it.
But now scientists and advocacy groups are hopeful “the search for a vaccine that will eventually stop the spread of HIV virus still continues”.
Prof Omu Anzala, a researcher at the Kenya Aids Vaccine Initiative, Institute of Clinical Research, University of Nairobi explains there are still high hopes in HIV vaccine development in the country.
“As researchers, we were also taken aback when the research was actually stopped because of futility.
We had high hopes because the vaccine being tasted was based on a previous vaccine that had been tested in Thailand called RV144. But nonetheless, these are the challenges of HIV vaccine development,” said Anzala.
The prof, whose organisation is involved in conducting clinical trials for HIV and Aids, notes the HVTN 702 study is one of the many trials ongoing in different parts of the globe.
“So, while this information is disappointing, Kenyans should not be completely disappointed because work still continues,” he said.
“As a country we have not stopped. We continue to learn from each trial,” he added during a media science café organised by International Aids Vaccine Initiative (IAVI) and Mesha Science, an association of science journalists.
HVTN 702, also referred to as Uhambo—meaning travel or journey in Zulu—is a Phase 2b/3 study that began in 2016 to rest an experimental prime-boost vaccine regimen.
It was based on the only vaccine regimen that to date showed protection from HIV, the RV144 clinical trial conducted in Thailand.
The study, which involved 5,407 HIV-negative sexually active men and women aged 18 to 35 years at 14 sites across South Africa, gave a clear pointer of a ‘long way to go’ in creating a vaccine for sub-Saharan Africa, which has the highest HIV epidemic in the world.
According to NIAID, the volunteers either received the vaccine regimen or placebo injections.
In an interim analysis of data on Jan 23, it was found that 129 HIV infections occurred among the vaccine recipients and 123 HIV infections occurred among placebo recipients, meaning it was ineffective.
But just how does this result reverberate across developing nations, especially Kenya?
More than a third new HIV infections globally occur among young women in Africa. Increasing intervention programmes is vital.
A recent report by National Aids and Sexually Transmitted Infections Control Programme (NASCOP) revealed that at least eight counties account for 50 per cent of all new HIV infections in the country.
In Kenya’s context, where the epidemic has crept into the adolescents’ arena-the news is a sad one to young people aged between 15 and 24 years.
Approximately, 1.6m people are living with HIV, with an incidence f 1.02 per 1,000 people in 2018.
Of the 15-24 cohort, new infections among women were double compared to men at 11,000 cases and 5,000 respectively.
Professor Kenneth Ngure, from the Jomo Kenyatta University of Agriculture and Technology’s School of Public Health, who is also conducting research addressing the needs of adolescent girls and young women with choices in HIV prevention says “There is still hope, there will be a vaccine soon”.
Ngure notes that even as “researchers pursue the vaccine road, there are still other biomedical prevention methods such as the use of PrEp, Anti Retroviral Therapy (ART) and other options such as the use of condoms that are as effective in the fight against the pandemic”.
And because there are other candidates in the trial, Ngure believes, the news, “will not diminish the quest for an HIV vaccine”.
“We still need a vaccine as part of the tool box in tackling HIV/Aids”, he added.
However, one thing is clear: developing HIV vaccine has perplexed researchers since the 1980s because of the complexity of the virus, thanks to its high levels of mutation and different strains.
In 1997, for example, then US president Bill Clinton pledged money to an effort to find a vaccine within10 years. Decades later, no discovery has been made.
“I think this result is a really important reminder of just how hard it is to develop a HIV vaccine,” said Mitchell Warren, executive director at AVAC, an international non-profit focused on development and delivery of HIV prevention tools in a statement.
Dr Kundai Chinyenze, Executive Medical Officer at IAVI, said the world still needed a HIV vaccine to complement current interventions and to end the epidemic.
“We need to continue with the search for alternative tools and weapons that can be used to prevent HIV/Aids,” said Chinyenze.
Across the divide, there is still hope of finding a vaccine. This wasn’t the only ongoing vaccine trial, according to researchers.
There are three other late-stage vaccine trials. Two of them, called Imbokodo and Mosaico, use a “mosaic” approach aimed at protecting against a wide variety of global HIV strains.
They are sponsored by Janssen Vaccines & Prevention. Results for Imbokodo are expected in 2021.
There is also a trial examining the effectiveness of combining an HIV vaccine with pre-exposure prophylaxis — which is a daily pill used to prevent HIV.
Unlike HVTN 702, which was only conducted in South Africa, the Imbokodo study is conducted in other parts of Africa, providing even more opportunity to engage closely with communities.
Professor Anzala explains that several vaccine research initiatives at the institution are also trying to unlock the puzzle locally.
“At KAVI, we have our own clinical trials that are ongoing, including elicitation of broadly neutralising antibodies, infusion of neutralising antibodies and (mosaic-which is looking at various antigens,” he added.
The current clinical trials at KAVI are in phase one, which looks at safety and immune response meaning products have just finished animal studies and are being tried on humans.
Phase two, he continues, will look at a more immune response and safety with a higher population before it goes to phase three where the researchers answer the question on whether the vaccine really works.
Although HIV/Aids incidences have been on the decline thanks to sustained prevention campaigns, more needs to be done, says Anzala.
He adds, even as we explore other preventive measures, there is need for a concentrated communication and advocacy programmes to educate people that actually HIV/Aids has not gone away.
“As an effort towards control, we need to see a lot of communication. In real sense, HIV/Aids has not gone away,” he noted.
At the prevention level too, there is need to know who is getting infected to be able to conduct a targeted prevention initiatives.
“As a country we need to know who is being infected; know pockets of high infection rates…This will enable target our preventive measures to those areas.
“What will prevent HIV in Kisumu, might be different from other areas like Mombasa, Nairobi,”added Anzala.
Shrinking HIV funding in developing nations is still curtailing research programs explains Anzala, but there are organisations still supporting research for HIV vaccines.
Only recently Kenya received what officials termed as the highest single grant from Global Fund to fight HIV, malaria and tuberculosis at Sh42.7 billion.
“But what is really going to stop the spread of the virus is a preventive vaccine,” said Anzala.
The study found no safety concerns and even the advocates supported its integrity… “As advocates, we are happy with the integrity of the trial.
“We now need to invest now more than ever in HIV research to halt new infections,” added Rosemary Mburu, Executive Director at WACI Health.
Berliane Anyango, youth advocate with Athena Initiative, HomaBay County thinks researchers need to work more closely with healthcare providers and advocates to ensure research is truly community-owned.
“Many people now look strongly into HIV vaccine as the best way of preventing HIV/Aids as majority of young people see daily pill taking as a burden.
“I urge collaboration between the researchers, scientists, advocates and healthcare providers to achieve this,” said Anyango.
